**Exhibit 10.3**

**FIRST AMENDMENT TO MASTER LOAN AND SECURITY AGREEMENT**

**             THIS FIRSTAMENDMENT**TO MASTER LOAN AND SECURITY AGREEMENT (the “Amendment”), dated as of May15, 2001, by and between Eligix, Inc. (the “Borrower” or “Eligix”), a Delawarecorporation, having its principal place of business and chief executive officeat 200 Boston Avenue, Medford, Massachusetts, 02139, and TRANSAMERICA BUSINESSCREDIT CORPORATION (the “Lender”), a Delaware corporation, having its principaloffice at Riverway II, West Office Tower, 9399 West Higgins Road, Rosemont,Illinois, 60018.

WITNESSETH:

**             WHEREAS,**the Borrower and the Lender are parties to theMaster Loan and Security Agreement, dated as of July 28, 1999 (as amended, the“Loan Agreement”; capitalized terms used herein shall have the meaningsassigned to such terms in the Loan Agreement unless otherwise defined herein);

**             WHEREAS,**Eligix and BioTransplant, Inc., a Delawarecorporation (“BioTransplant”), have agreed to merge; and

**             WHEREAS,** the parties hereto desire to amend the LoanAgreement in the manner set forth herein.

**             NOW,THEREFORE,** in consideration of the foregoing and for other good and valuableconsideration, the Borrower and Lender hereby agree as follows:

             1.          **Amendmentto Loan Agreement**. Effective as of the date this Amendment is fully executed by the Lenderand Borrower hereof, and subject to the satisfaction by the Borrower ofconditions as determined by Lender, the Loan Agreement is hereby amended to addBioTransplant as a joint and several borrower and party to the Loan Agreement(hereafter, Eligix, and BioTransplant shall collectively be referred to as“Borrower”).

             2.          **Representationsand Warranties of Eligix.**

                           (a)         Sine July 28, 1999, there has occurredno development, event or change that has had or could reasonably be expected tohave a Material Adverse Effect.

                           (b)        No Default or Event of Default hasoccurred and is continuing.

                           (c)         The representations and warranties ofEligix contained in Section 4 of the Loan Agreement are true and correct in allmaterial respects on the date hereof as though made on and as of the datehereof, except to the extent that such representation and warranties expresslyrelate solely to an earlier date (in which case such representations andwarranties were true and correct on and as of such earlier date).

                           (d)        This Amendment constitutes the legal,valid and binding obligation of Eligix, enforceable against Eligix inaccordance with its terms, except as enforceability may be limited bybankruptcy, insolvency and other laws affecting creditors’ rights generally andby general principles of equity.
             3.          **Representationsand Warranties of BioTransplant**.  This Amendment constitutes the legal, valid and bindingobligation of BioTransplant, enforceable against BioTransplant in accordancewith its terms, except as enforceability may be limited by bankruptcy,insolvency and other laws affecting creditors’ rights generally and by generalprinciples of equity.

             4.          **Conditionsto Amendment.**  Theobligation of the Lender to consummate this Amendment is subject to theLenders’ receipt of the following, in form and substance satisfactory to theLender and its counsel:

             (i)          acertificate of the Secretary or an Assistant Secretary of BioTransplant(“Secretary’s Certificate”) certifying:

(a)         that attached to the Secretary’sCertificate is a true, complete, and accurate copy of the resolutions of theBoard of Directors of BioTransplant (or a unanimous consent of directors inlieu thereof) authorizing the execution, delivery, and performance of the LoanAgreement, the other Loan Documents, and the transactions contemplated herebyand thereby, and that such resolutions have not been amended or modified sincethe date of such certification and are in full force and effect;

(b)        the incumbency, names, and truesignatures of the officers of BioTransplant authorized to sign the LoanDocuments to which it is a party; and

(c)         that attached to the Secretary’sCertificate is a true and correct copy of the Articles or Certificate ofIncorporation of the Company, as amended, which Articles or Certificate ofIncorporation have not been further modified, repealed or rescinded and are infull force and effect;

             (ii)         such other agreements and instruments as the Lender deemsnecessary in its reasonable discretion in connection with the transactionscontemplated hereby.

             5.          **Miscellaneous.**

                           (a)         Except as expressly amended herein, allof the terms and provisions of the Loan Agreement and the other Loan Documentsare ratified and confirmed in all respects and shall remain in full force andeffect.

                           (b)        Upon the effectiveness of thisAmendment, all references in the Loan Documents to the Loan Agreement shallmean the Loan Agreement as amended by this Amendment and all references in theLoan Agreement to the “this Agreement”, “hereof”, “herein”, or similar terms,shall mean and refer to the Loan Agreement as amended by this Amendment.
                           (c)         The execution, delivery andeffectiveness of this Amendment shall not, except as expressly provided herein,operate as an amendment to or waiver of any right, power or remedy of theLender under any of the Loan Documents, or constitute an amendment or waiver ofany provision of any of the Loan Documents.

                           (d)        This Amendment may be executed by theparties hereto individually or in combination, in one or more counterparts,each of which shall be an original and all of which shall constitute one andthe same agreement.  This Amendment maybe executed and delivered by telecopier with the same force and effect as ifthe same were a fully executed and delivered original manual counterpart.

                           (e)         This Amendment shall constitute a LoanDocument.

             6.          **GOVERNINGLAW**.  THE VALIDITY,INTERPRETATION AND ENFORCEMENT OF THIS AMENDMENT SHALL BE GOVERNED BY THE LAWSOF THE STATE OF ILLINOIS WITHOUT GIVING EFFECT TO THE CONFLICTS OF LAWPRINCIPLES THEREOF.

**Signature page to follow**.

**Signature page to Amendment.**

**             IN WITNESSWHEREOF,**the parties hereto have caused this Amendment to be duly executed anddelivered by their respective duly authorized officers as of the date firstabove written.
 BORROWER   ELIGIX, INC.   By:/s/ James R.  Fitzgerald    Name:  James R. Fitzgerald  Title:  Senior Vice President Hereunto Duly  Authorized    BORROWER   BIOTRANSPLANT  INCORPORATED   By:/s/ Richard V. Capasso    Name:  Richard V. Capasso  Title:  Vice President Finance Hereunto Duly  Authorized    LENDER   TRANSAMERICA BUSINESS  CREDIT CORPORATION   By:/s/ Allen M. Sailer    Name:  Allen M. Sailer  Title:  Vice President Hereunto Duly  Authorized